As the Washington Nationals take on the St. Louis Cardinals in the National League Division Series, fans of D.C. baseball are experiencing rooting for a Washington team in the postseason for the first time since 1933. The Nats’ 3-2 win over the Cards Sunday gave Washingtonians the first baseball playoff win they can remember, unless they’re over 85 or so.

D.C. fans can’t even remember the old Senators unless they’re nearly 50. Young children growing up today have a chance to watch the Nats, but an entire generation of D.C. fans didn’t have a team to call their own from 1972 to 2004.

Those fans, who range from high school to middle age, grew up without a team in the nation’s capital, but it’s not quite accurate to say that they didn’t have a rooting interest. Many Washingtonians became fans of the Baltimore Orioles after the Senators left Washington in 1971. The O’s had 14 consecutive winning seasons after the Senators abandoned town. Then the Birds had another fine stretch between 1992 and 1997, with only one losing campaign.

The D.C. media treated the Orioles almost as if they were from Washington, especially after the O’s won the World Series in 1983. Coverage in the sports pages and local TV sportscasts became equal to that afforded to the Bullets and Capitals, and second only to that given to the Redskins. Thousands of fans drove up I-95 from the D.C. area for every Orioles game.

D.C. fans helped Baltimore set attendance records in the 1980s and 1990s. In 1992, when the O’s averaged more than 44,000 fans, a fan survey found that 21.9 percent of fans at Camden Yards hailed from the D.C. metropolitan area. Other estimates suggested that one-third to even half of those buying seats at Orioles games came from the Washington area.

For some D.C. fans, Cal Ripken and Eddie Murray rated just a notch below local heroes John Riggins, Joe Theismann, and Art Monk.

Meanwhile, for decades Washington tried to get a major league team, but several near misses kept the national pastime out of the nation’s capital. In the 1990s and early 2000s, Orioles owner Peter Angelos did his best to block D.C. from getting a franchise, contending that his O’s would suffer at the gate. Finally, when the Montreal Expos moved to D.C. in 2005, D.C. secured its own team. Angelos didn’t do Nats fans any favors with a TV contract that left the Nats practically invisible to many Washingtonians early on.

Fast forward to 2012. Crowds at Nationals Park averaged 30,010 fans per game. Despite local and national criticism, those numbers were more than respectable because it was the franchise’s first winning season. The area around Nationals Park also lacks the bars, restaurants, and retail stores that surround many other major league ballparks such as Camden Yards. Still, Nats merchandise sales are going through the roof, and TV ratings are up significantly over last year.

But many Washingtonians still pull for the Orioles. They grew up rooting for the O’s, watching Chuck Thompson and Brooks Robinson call the games on TV and listening to Jon Miller do play by play on the radio. Now that Baltimore has made the playoffs for the first time in 15 seasons, D.C. fans are left with an interesting quandary.

Should they also root for the Orioles to win? As a sports fan, is it okay to root for two different teams? For people who live in Laurel, halfway between the two cities, the answer is “of course.” For those who live in Frederick or Annapolis, each about the same distance from D.C. and Baltimore, the answer is “yes.” But for those in the D.C. area, the answer is not so simple.

Old loyalties die hard. Many D.C. fans have great memories of Memorial Stadium and Camden Yards. The Orioles, with their illustrious history, and Baltimore with its charm, offered unforgettable times for D.C. fans. But it was never permanent.

It didn’t hurt that the O’s of the early 1980s resembled the Redskins of the same era. Both teams did things the right way on and off the field. It was rare to have troublemakers on the teams. There were a few stars, but humble, blue-collar players served as the glue that held the teams together.

Now that the Orioles are in the American League Division Series, D.C. fans may be tempted to root for the team in black and orange, especially since they’re playing the New York Yankees. New York is a natural rival of D.C., and those who remember the Senators will also remember the Yankees’ dominance over the old Nats.

But you can’t go back to your old girlfriend and just be friends. Rooting for the Orioles was then; this is now. This is the Nats’ time. They deserve the full attention of D.C. fans. The O’s had their chance. You can’t live in the past, no matter how glorious it was. The Nats are making their own memories. The O’s belong in the scrapbook, at least for D.C. fans. Ripken and Murray will always be remembered. But now it’s Stephen Strasburg and Bryce Harper, Adam Zimmerman and Jayson Werth. Fittingly, Davey Johnson, who played for and managed the Orioles, now manages the Nats.

Baltimore is a totally different place than D.C. Does anyone root for both the Redskins and the Ravens? Not many fans would boast of that. You have to choose between the Nats and the O’s, and if you’re from D.C., the choice is clear. Baltimore fans can root for the Caps but that’s because they don’t have a hockey team. The Maryland Terrapins are closer to D.C. but they belong to both cities. But when it comes to pro sports, D.C. and Baltimore are two very distinct markets.

Nats fans may glance at the highlights and skim the articles about the team in Charm City. Maybe even pull for them out of the corner of your eye. But don’t get fully invested. That gets too complicated. Keep it simple and stick with the red, white, and blue.

Mike Frandsen is a freelance writer covering all things Redskins. His work can be found on Examiner.com.